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Biomedical subjects

J Grun

Publications and source records attributed to J Grun.

At least 19 recordsLinked to original sources
PubMed2001

Methods for developmental studies of fear conditioning circuitry.

Psychophysiologic studies use air puff as an aversive stimulus to document abnormal fear conditioning in children of parents with anxiety disorders. This study used functional magnetic resonance imaging (fMRI) to examine changes in amygdala activity during air-puff conditioning among adults. Blood oxygen level-dependent (BOLD) signal was monitored in seven adults during 16 alternating presentations of two different colored lights (CS+ vs. CS-), one of which was consistently paired with an aversive air puff. A region-of-interest analysis demonstrated differential change in BOLD signal in the right but not left amygdala across CS+ versus CS- viewing. The amygdala is engaged by pairing of a light with an air puff. Given that prior studies relate air-puff conditioning to risk for anxiety in children, these methods may provide an avenue for directly studying the developmental neurobiology of fear conditioning.

Adult↗
PubMed1999

Childhood anxiety: integrating developmental psychopathology and affective neuroscience.

This article reviews progress in research on childhood phobia, generalized anxiety, and separation anxiety disorders from the perspectives of developmental psychopathology and affective neuroscience. These perspectives represent two organizing theoretical schools in the realms of clinical and basic science research. Studies in developmental psychopathology suggest the need to identify specific subgroups of children with one of these anxiety disorders who are particularly at risk for anxiety disorders in adulthood. Studies in affective neuroscience suggest potential neurobiological avenues for identifying such children who face a particularly high risk for chronic anxiety disorders.

Anxiety Disorders↗
PubMed1987

Magnetic resonance imaging of parasitic tapeworm larvae Taenia crassiceps cysticerci in the peritoneal cavity of mice.

Because of their long T2 relaxation time (400 ms), larvae of the tapeworm Taenia crassiceps can be distinctly imaged in the mouse peritoneal cavity by NMR. An echo time of 400 ms sharply contrasted the parasites against the surrounding abdominal organs. A rapid, quantitative assay for parasite load can be obtained by recording the amplitude of a spin echo with no applied gradients at an echo time of 400-1000 ms. The T2 of the vesicular fluid of the human parasite Taenia solium was also long (600 ms), indicating that the same approach (long TE and long TR) can be used to image this parasite for diagnosis of human cysticercosis by NMR imaging.

Animals↗
PubMed1976

Immunoglobulins of the chicken antibody to Newcastle disease virus (Mukteswar and F strain).

The qualitative and quantitative development of chicken immunoglobulins in response to R2B (Mukteswar) and F strain of Newcastle disease virus was studied. One primary (R2B) and two secondary (R2B - R2B, F - R2B) vaccination trials were conducted. Sera was collected at weekly intervals and analyzed. There was an increase in total serum protein content in parallel to an increase in serum neutralizing (SN), hemagglutination inhibition (HI), and precipitating antibodies. The SN, HI and precipitating activities were detected both in IgM and IgG immunoglobulins when sera were treated with mercapto-ethanol. However, Sephadex G-200 fractionated sera showed only SN activity in the IgM fraction, whereas the IgG fraction showed both HI and SN activity. Serum IgM antibodies appeared during the first week following vaccination, then diminished, then rose again following secondary vaccination. Apparently, immunoglobulin induction and serological activities were not significantly influenced by the age of the chickens.

Animals↗
PubMed1975

Serum electrophoretic pattern of chickens vaccinated with R2B (Mukteswar) and F strain of Newcastle disease virus.

Sera from NDV (Mukteswar and F strain) vaccinated chickens of various age groups were subjected to paper, starch-gel and immunoelectrophoresis. An increase in total serum protein, gamma globulin, alpha globulin, and a decrease in beta globulin and albumin concentrations was observed in adult birds. The concentration of the various serum proteins varied widely depending upon the age of the other test birds. IgM and IgG band characteristics did not differ in sera from vaccinated and unvaccinated birds. The one transferrin band observed in the sera from unvaccinated chickens was not observed when chickens were vaccinated with the R2B vaccine. However, this transferrin band was again observed in the sera of chickens revaccinated with the R2B. No such changes were evident in the sera of chickens vaccinated with F strain only or followed by an R2B vaccination.

Alpha-Globulins↗
PubMed1975

A transovarian transmission study of Marek's disease in Japanese quail.

Experiments were conducted to determine if transovarian transmission of the JM strain of Marek's disease virus (MDV) occurs in Japanese quail. In one experiment, parent quail were infected with MDV when one-day-old; in another experiment, parent quail were infected when seven weeks old. No precipitating antigen or cytopathic or infective agent was isolated from the egg yolks, embryos, newly hatched quail, or progeny quail of the infected parents. During the eight weeks observation period, the progeny of infected parents showed no clinical symptoms, mortality, gross or microscopic lesions, MD viremia, or antibody. However, an MD-specific fluorescent antigen was observed in fibroblast and kidney cell cultures from embryos of parents infected at one day of age. Approximately 10% of the embryos contained this fluorescent antigen. Fluorescent antigen was not observed in cultures from embryos of quail infected at the age of seven weeks or control quail.

Age Factors↗
PubMed1975

Marek's disease in Japanese quail -- a pathological, virological and serological study.

Experimental studies were performed to see whether Japanese quail (Coturnix coturnix japonica) are susceptible to JM strain of Marek's disease virus (MDV). In three identical trials, a total of 120, one-day-old quail were inoculated intra-abdominally with 0.2 ml. of chicken blood infected with MDV (JM strain) and raised in FAPP isolators. Uninfected controls were inoculated with normal saline only and raised separately. During the 18-week post infection observation period, 65-80% of the infected quail died within six weeks, while the highest mortality in control groups was only 0-5%. In each trial, ocular lesions with or without unilateral or bilateral blindness and signs of torticollis were evident in a few quail after 10-14 weeks. Gross and microscopic lesions suggestive of MD were observed 14 days on. The most pronounced lesions were observed in lungs. Neural tissues were least affected. In general, females were more susceptible than males. MD-specific fluorescent and precipitating antigens were detected in different visceral tissues, buffy coat and cultured macrophages of infected quail. Fluorescent antigen appeared at 6-7 days after infection, whereas precipitating antigen appeared after 12-15 days. Viral (MDV) infectivity tests in cell cultures and bioassay in one-day-old chicks and quail demonstrated that infected quail become viremic around the seventh day post infection. A cytopathic agent similar to MDV was also isolated from quail. Neither Newcastle disease virus nor a bacterial agent was isolated from the quail. MD-specific fluorescent precipitating antibodies were present in the egg yolk and plasma of both infected sick and infected symptomless quail. The earliest detectable plasma MD antibody appeared in 14-21 days. Such findings were not observed in quail from parent stock and controls. Our studies demonstrated that Japanese quail are susceptible to JM strain of MDV.

Animals↗